1. Field of the Invention
This invention relates to skin-care compositions, and in particular, pertains to a skin-firming cream and an eye-firming cream, comprising at least one component that supports the collagen structure (firming), and at least one component that supports the body's own defense/repair mechanisms (protective), and most preferably, at least one component that supports the skin lipid system (barrier).
2. Description of the Related Art
Under normal conditions, human skin is capable of regulating its own moisture content, until the normal aging process sets in and skin generally becomes dryer. There are numerous prematurely occurring skin problems, however, such as dry skin, sagging skin, and other prematurely aging skin conditions and skin damage, that may occur in individuals of any age if they are exposed to harsh environmental conditions, such as over-exposure to the sun's rays. Thus, active young adults in their mid to upper 20's to their 40's may find to their dismay that their skin is beginning to have problems that are normally associated with much older people, particularly if they spend much time outside with their skin exposed without protection to sunlight, wind, and/or low humidity.
Because the treatment of skin problems is complex, and because most of these prior products are aimed at a particular limited aspect of skin damage, multiple products must be used to address the problems. A large portion of the cosmetic industry is devoted to trying to remedy one or more these skin problems, such as by providing various creams, lotions and other products. These skin-care products range from simple moisturizing preparations, containing main ingredients such as glycerin or tocopheryl acetate, to complicated formulations designed to prevent or repair particular types of skin damage. The moisturizing preparations generally rely either on occlusive substances that form a barrier on the skin, for example, paraffin or petrolatum, so that water is prevented from transdermally escaping through the skin, or on intradermal substances, such as glycerol that bind the water in the skin.
There are many skin-care products that include plant extracts. Examples include the composition of Pinnell (U.S. Pat. No. 6,524,599) containing milk thistle extract, soybean protein and alpha tocopherol, either singly or in combination. The disclosure of this patent and all other patents and publications referred to herein is incorporated herein by reference.
An example of a natural non-botanic product found to improve and stabilize the hydration of the human skin is ectoin, (s)-1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (C6H10N2O2) obtained from extremely halophilic bacteria, such as Ectothiorhodospira halochloris, found in salt lakes, saline soils, deserts and seawater. Ectoin is known to play a role in the osmoregulation of these organisms, being compatible with the metabolism of the cells, even in high concentrations. Ectoin is amphoteric and binds water molecules, forms large hydration shells, stabilizes the natural structure of biopolymers such as proteins, nucleic acids and biomembranes, and minimizes the denaturation of these biopolymers that usually occurs when water is lost, by counteracting this process. See U.S. Pat. No. 6,403,112. As a cosmetic raw material, ectoin has been found to protect the skin from being damaged by environmental stress factors, such as heat, cold, UV radiation, and harmful environmental chemicals, by supporting the repair and protective mechanisms of the cells. For example, studies have shown that ectoin inhibits the signaling cascade brought about by UVA-radiation in human keratinocytes as well as UVA radiation-induced formation of mitochondrial DNA mutations in human dermal fibroblasts. In addition, ectoin regulates the natural moisture in cells, preventing them from drying out, so that the skin remains moist and supple for a longer period of time, protects cell membranes against various surfactants, helps to inhibit the formation of sunburn cells, induces faster formation of heat-shock proteins, and protects the skin immune system by preventing damage to Langerhans cells. Commercially produced ectoin (RONACARE™, Ronacare, division of Merck KGaA, Darmstadt, Germany) contains about 96% ectoin, with the remainder being hydroxyectoin and trace elements. It is easily accepted by the cells, is compatible with the cells' inherent metabolism, has a high level of activity, is non-toxic and chemically and biologically stable.
Centella asiatica, or tiger grass, is a perennial creeping tropical plant, that has been known and used by East Indian, American Indian, Chinese and Indonesian traditional doctors for thousands of years for wound-healing, sedative, analgesic and antibiotic treatments. For about 30 years, pharmaceutical products have been taking advantage of the healing properties of Centella asiatica, successfully using it to accelerate post procedure healing, to stop the inflammatory phase of hypertrophic scars and keloids and many other indications. The active constituents of C. asiatica are two triterpenic saponines, asiaticoside and madecasoside, which are derived respectively from asiatic acid (2 Ó, 6β, 24-trihydroxy-urs-12 (13)-en-28 oic) and madecassic acid (2 Ó, 6β, 24 Ó-tetrahydroxy-urs-12 (13)-en-28 oic). These constituents are not very abundant when using a standard plant extract of Centella asiatica. The titrated extract of the leaves of Centella asiatica (TECA), used herein, is a standardized product of Roche Nicholas Laboratories. TECA is the combination of three of these active ingredients—asiatic and madecassic acid (54–66%) and asiaticoside (36–44%). It is used for wound-healing, for example, by increasing the cellular proliferation and collagen synthesis at the wound site, venous insufficiency, anti-wrinkle toning, cellulite and stretch marks, and has also been found to be effective in the cicatrisation of burns, as well as providing healing and soothing properties to the skin. Extracts of Centella asiatica containing various levels of the active ingredients have also been shown to have effectiveness in wound healing and related treatments, as well as to have anti-microbial properties.
To prevent harmful substances from adhering to or entering the skin, and to prevent transepidermal water loss, various skin barrier products have been produced that provide an intact coating over the skin. Petrolatum products, such as AQUAPHOR™, provide a simple barrier, but do not help in skin repair. Other products have also been formulated for skin barrier repair. In human skin, ceramides are the major lipid constituents of the stratum corneum and play a crucial role in the skin barrier function and water retention in the skin. A balance of cholesterol, ceramides, glycosylated ceramides and triglycerides (barrier and physiologic lipids) is essential to maintain optical skin condition. Glycosphingolipids, such as ceramides, which promote differentiation, and glycosylated ceramides, which enhance proliferation, have been shown to play a role in maintaining an intact skin surface barrier. The BMX™ complex of Barnet Products Corp. (Englewood Cliffs, N.J.) is a lipid complex that mimics biological membranes and provides a stable matrix, and creates a delivery system to suspend the critical components and facilitate delivery into the stratum corneum of the skin. BMX™ complex comprises lipids isolated from plant material (Hordeum vulgare (barley) and Solanum lycopersicum (tomato)) and helps in lipid retention in the skin. In particular, the various plant extracts in this product are combined in a final ratio to yield a composition approximately as follows: 20% phytosterols, 30% triglycerides, 40% hydrocarbons and branched esters, 10% ceramides and other phytosphingolipids.
SEPILIFT DPHP™ (dipalmitoyl hydroxyproline)(Seppic, Fairfield, N.J.) exhibits triple firming action: it stimulates remodeling and contraction of collagen fibers, protects elastic fibers against enzymatic breakdown, and scavenges free radicals. Products containing SEPILIFT DPHP™ include moisturizers and lip conditioners.
BOIS II™ (Barnet Products Corp., Englewood Cliffs, N.J.) is a proprietary raw material containing various polar and non-polar lipids from Santalum album (sandalwood), Phellodendron amurense bark (cork tree), and Hordeum distichon (barley grain) extracts. The extract is obtained from aged wood pulp and grains, which are washed and dried, then ground to a fine powder and extracted with grain oil as an extraction medium, without the use of solvents, to yield medium chain hydrocarbons, long chain alcohols, glycolipids, flavonoids, fatty acids and triglycerides. It specifically contains various lipids inherent to these plants extracted in a proprietary process that yields, among others, medium chain hydrocarbons, glycolipids, fatty acids and triglycerides, all of which are essential constituents of the lipid barrier of the skin. BOIS II™ has been found to reduce transepidermal water loss, increase skin hydration, and improve skin suppleness.
The skin around the eyes is particularly susceptible to damage from environmental stressors or stressful lifestyles, such as sagging, undesirable dark circles, or puffiness. Thus, for treatment of the skin beneath the eyes, cosmetic ingredients that are aimed at addressing one or more of these conditions have been produced. One such product is EYELISS™ (Sederma S. A., member of Croda International Group, Le Perray-En-Yvelines, France), which contains three active substances: hesperidin methyl chalcone (5%), derived from a flavonoid, hesperidin, present in citrus fruits, which decreases capillary vessel permeability; dipeptide valyltryptophan (VW)(0.1%), a peptide from the traditional Japanese fermented rice beverage sake, which increases the frequency of lymphangion contraction; and palmityoyl-Gly-Gln-Pro-Arg (Pal-GQPR)(300 ppm) SEQ ID NO: 1, a fragment of human immunoglobulin, which restores skin elasticity and firmness, plus water, glycerin, and steareth 20 dipeptide-2 (“dipeptide”). This combination addresses the problems of capillary permeability related to irritation, hypertension, tiredness and the effects of age causing the walls of the network of vessels crossing the eyelid to have increased leakage of water and protein into surrounding tissues, especially sub-orbitally. It also reduces the tissue sagging and inflammation that contribute to fluid stasis, and reduces the problem of insufficient lymphatic drainage. This is because hesperidin methyl chalcone, derived from Hesperidin, has anti-edematous properties and decreases capillary permeability, dipeptide increases the frequency of lymphangion contraction, thereby enhancing the removal of fluids, and Pal-GQPR, a fragment of human immunoglobin, acts on secretion of cytokine IL6, thereby helping preclude inflammations.
An additional preferred component of the eye-firming cream is SK-INFLUX™ (Centerchem, Inc., Stamford, Conn.), which helps to maximize the skin barrier, and essential factor in the delicate eye area where the skin thickness is only that of approximately 3–5 sheets of paper. SK-INFLUX™ is a lipid concentrate used to improve the skin barrier, through moisturization, anti-aging and anti-wrinkle effects, skin repair, and skin protection. The lipid concentrate includes a ceramide complex (1.5%), which contains ceramide I (0.001%), ceramide III (0.5%), ceramide IIIB (0.5%), and ceramide VI (0.5%); cholesterol. (1.5%), free fatty acid (about 3.5%) and phytosphingosine (0.5%). Ceramides I, III and VI are required in restoration of damaged and sensitive skin.
It is therefore an object of the invention to provide a single skin-firming cream that enhances collagen biosynthesis, improves cell repair, supports the skin immune system, and improves the skin barrier. It is a further advantage to provide an eye-firming cream with these same features, plus having the benefit of repairing bags under the eyes as well as working to prevent their formation.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.